"A powerful explosion went off at 3:20 am in the village of Dugulubgei close to the village mosque. Fragments of the bodies of two unidentified people were found at the scene," the regional Interior Ministry said.

Russia's powerful Investigative Committee named the preliminary cause of the explosion as the two dead "blowing themselves up."

It said that the explosion took place at the gates of the village's graveyard close to the mosque. An earlier report by a news agency quoted a law enforcement source as saying that the victims apparently blew themselves up accidentally while planting the IED.

The Investigative Committee said that operatives found a large amount of arms: shells, grenades, a Kalashnikov and two pistols at the scene.

The blast occurred close to the town of Baksan, where militants set off explosions at the hydroelectric power station in 2010, killing two guards.

Kabardino-Balkaria, which has ski resorts and is popular with climbers, is considered one of the more peaceful areas of the Russian Caucasus, a mountainous region that is plagued by an Islamist insurgency, with near daily attacks on security officials.